High speed waveguide switch



Dec. 15, 1959 w. T. BROWN HIGH SPEED WAVEGUIDE SWITCH Filed Sept. 27, 1957 M 3 w w\ b fitter/755s.

United States Patent HIGH SPEED WAVEGUIDE SWITCH William T. Brown, Fort Wayne, Ind., assignor to International Telephone and Telegraph Corporation Application September 27, 1957, Serial No. 686,694

14 Claims. (Cl. 333-7) This invention relates to waveguides for microwave transmission and more particularly to switching means for selectively connecting a main waveguide section to one of two branch waveguide sections.

Waveguides, which are conventionally formed as elongated tubing having a rectangular cross-section, are used for conducting extremely high frequency currents in the microwave region. In the design of certain types of microwave equipment, it is frequently found desirable to provide two antennas in conjunction with a single transmitting or receiving apparatus and it is therefore necessary to accept or transmit energy to or from either antenna. Waveguide assemblies have therefore been provided having a main section coupled to the transmitting or receiving apparatus and two branch sections coupled respectively to the two antennas. Switching apparatus has also been proposed for selectively coupling one or the other of the branch waveguide sections to the main waveguide section, however, such switching apparatus known to the applicant has been relatively complex, diflicult to assemble, and in particular not sufficiently fast acting.

I have found that an extremely fast acting waveguide switch mechanism can be provided by utilizing a first magnet member having a thinsteel vane pivotally hinged to one end thereof so that the vane has the same magnetic polarity as the end of the magnet member. The vane extends into the waveguide assembly through an opening therein and has two positions respectively closing and short-circuiting the two branches thereby selectively connecting the main waveguide section to one or the other of the branches. Another magnet member surrounds the main waveguidewith the vane being disposed magnetically between its poles. One of the magnetic members is an electromagnet and the other a per- .manent magnet, the electromagnet having a coil arranged to be selectively energized in opposite senses so that the core is polarized in opposite directions in response thereto. With this arrangement, two strong magnetic poles of opposite polarity are provided in very close contact, i.e., the vane and one of the poles of the other magnet member. Pulsing the electromagnet so that the vane has the same magnetic polarity as the adjacent pole of the other magnet member causes the vane to be violently and very rapidly repelled toward the opposite pole of the other magnet member. The hinging of the vane to one end of the first magnet member provides a pivotal connection having essentially no friction since the hinged connection of the vane essentially floats in the magnetic field. Furthermore, the edges of the vane are magnetically sealed to the waveguide walls so that the vane makes an effective short circuit therewith. Also, due to the magnetic attraction between the vane and the adjacent pole of the other magnet member, there is very little tendency for the vane to bounce, and since the switching action is positive due to the strong magnetic fields involved, relatively large amounts ofpower can be the H-plane of the waveguide assembly, the standing switched. I have further found that since the vane is in I 2,917,719 Patented Dec. 15, 1959 ICC wave ratio is good and good impedance matching to the main waveguide section is obtained during the switching transient.

It is accordingly an object of this invention to provide waveguide apparatus having improved means for switching a main waveguide section to one or the other of two branch waveguide sections.

Another object of this invention is to provide a waveguide assembly having improved switching means characterized by its extremely fast action.

A further object of this invention is to provide waveguide apparatus having improved switching means characterized by its simplicity and ease of assembly.

Yet another object of this invention is to provide a waveguide assembly having improved switching means incorporating the desirable features set forth above.

The above mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

Fig. 1 is a view in perspective illustrating a waveguide assembly incorporating the preferred form of switching means of this invention;

Fig. 2 is a fragmentary exploded view showing the construction and arrangement of the magnetic vane of the embodiment of Fig. 1;

Fig.3 is a diagrammatic view useful in explaining the mode of operation of the embodiments of Figs. 1 and 2; and

Fig. 4 is a diagrammatic view, partly broken. away, illustrating the modified form of the improved waveguide switch of this invention.

Referring now to Figs. 1 and 2, there is shown a waveguide assembly, generally identified as 1, having a pair of branch waveguide sections 2 and 3 of conventional form merging into a main waveguide section 4, thereby defining a generally Y-shaped configuration. The waveguide sections 2, 3 and 4 are mechanically supported by a generally U-shaped frame member 5 formed of magnetic material, such as steel, having its upper leg 6 slotted, as at 7 and 8, for receiving and supporting the branch waveguide sections 2 and 3, and having its lower leg 9 slotted, as at 10, for receiving and supporting the main waveguide section 4.

The end 11 of the main waveguide section 4 intermediate the branch sections 2 and 3, i.e., at the apex of the V formed by the branch waveguide sections 2 and 3 with the main waveguide section 4 has an elongated slot 12 formed therein communicating with the interior of the waveguide assembly. A cover member 13 formed of magnetic material, such as steel, is arranged to be positioned on the end 11 of main waveguide section 4 to cover the opening 12 and is secured thereto in any suitable manner, as by screws 14. The cover member 13 has a portion 15 depending therefrom having a longitudinal semi-cylindrical groove 16 formed therein, portion 15 extending into the main waveguide section 4. An

elongated vane 17 formed of relatively thin magneticmaterial, such as steel, is provided having an enlarged upper edge 18 disposed in the longitudinal groove 16, as most clearly seen in Fig. 2. It will thus be seen that the enlarged edge 18 of vane 17 and the elongated groove 16 of the portion 15 of cover member 13 define a hinged pivot for the vane 17. Vane 17 is arranged to have two positions, one closing and short circuiting branch waveguide section 2 so that main waveguide section 4 communicates with and is coupled to the branch waveguide section 3, and the other short circuiting branch waveguide section 3 so that the main waveguide section 4 communicates with and is coupled to the branch Waveguide section 2.

In order to provide for rapidly switching the vane 17 from its first position to its second position, an electromagnet 19 is provided having an elongated laminated core 20 with its upper end 21 seated in a slot 22 in leg 6 of frame and with its lower end 23 abutting the upper surface of cover member 13. Core 20 may be held in assembled relation by a suitable bracket member 24 secured to the outer edge of leg 6 of frame 5 in any suitable manner, as by screws 25. Electrornagnet 19 has a winding 26 disposed on the elongated core 20; coil'26 has leads 27 and 28 brought out from its inner and outer ends and a center tap lead 29 which defines coil sections 30 and 31 with the end leads 27 and 28, respectively. As seen in Fig. 3, the two sections 30 and 31 of coil 26 are adapted to be selectively connected to an energizing source, such as battery 32, by double throw switch 33.

It is thus seen that with switch 33 positioned so that battery 32 energizes coil section 30 through leads 27 and 29, core 20 of electromagnet 26 may be assumed to be polarized with lower end 23 at south polarity and upper end 21 at north polarity. Likewise, it will be seen that with switch 33 positioned to connect battery 32 to energize coil section 31 through leads 28 and 29, the polarization of the core 20 will be reversed, i.e., with end 23 at north polarity and end 21 at south'polarity. It will now also be seen that the vane 17 will be at the same magnetic polarity as the end 23 of coil 29 to which it is hinged andfurther that thepivotal connection of the vane 17 will be essentially frictionless since the enlarged edge 18 of vane 17 essentially floats in the magnetic field of the core 20.

Referring again to Fig. 1, a pair of cylindrical permanent magnets 32 and 33 are provided respectively having one 'end-a'butting-theinner surface ofleg 9 of frame 5 on opposite sides of the main waveguide section 4. Permanent magnet members 32 and 33 are oppositely and iongitudinally polarized, i.e., the south polar extremity 'of magnet 32 abuts leg 9 of frame 5 while the north polar extremity of permanent magnet 33 abuts leg 9 of frame 5. A polepiece member 34 is positioned with pole piece portions 35 and 36 respectively abutting the other ends of permanentmagnets 33 and 32 and having polar extremities 37 and 38 respectively abutting the sides of main waveguide section 4 immediately adjacent the merger of branch waveguidesections 2 and 3 therewith. A portion 39 -joins'the pole piece portions 35 and 36 thereby providing a keeper bridge for the permanent magnets 32 and 33.

It will now be seen by additional reference to Fig. 3 that the magnetic vane 17 within the main waveguide section 4 is magneticallydisposed between the permanent magnet pole 'pieces37 and 38. Assuming now momentarily that switch 33 ispositioned so that battery 32 is connected to energize coil section 30 of electromagnet coil 26 so that the end 23 of core 21) is at south polarity, the vane 17 will likewise be at south polarity and will beattracted to the north-pole 33 of the permanent magnet assembly 3233, thereby closing and short-circuiting the branch waveguide section 2. Assuming now that the switch 33 is moved tothe other position so that battery 32 is connected to energize coil section 31 so that the end 23 of core 20 suddenly becomes polarized at north polarity, it will be seen that with the vane 17 also at a north polarity, it will be suddenly and violently repelled from the north polar extremity 33 of the permanent magnet assembly 3233 and simultaneously attracted toward the south polar extremity 37, thereby rapidlyto close and short circuit branch waveguide section 3. It willfurther be seen that the frame 5 being formed of magnetic material provides a return path for the magnetic flux of core 20 of electromagnet 19 when the vane 17 is at rest.

Referring now to Fig. 4, it will be seen that the relative positions of the electromagnet and permanent magnet members may be reversed. Here, with like elements being indicated by like reference numerals, elongated and longitudinally polarized permanent magnet 40 is provided with, for example, elongated slot 16 formed in its north polarized end 41. Enlarged edge 18 of vane 17 is again positioned in slot 16 and thus it will be seen that the vane 17 will likewise be at a north potential. Here, magnetic frame structure 42 is provided having polar extremities 43 and 44 respectively embracing the sides of main waveguide section 4 adjacent its merger with the branch waveguide sections 2 and 3 so that again the magnetic vane 17 is disposed magnetically between the polar extremities 43 and .44. Here, electromagnet coil sections 30 and 31 are disposed on the polar extremities 43 and 44 of the magnetic frame structure 42 and connected respectively to end leads 27 and 28 and to mid-point connection 29, as in the case of the embodiment of Figs. 1, 2, and 3. It will'further be seen that the magnetic frame structure 42 provides a magnetic return path for the permanent magnet 40 when the vane 17 is at rest since the south end 45 of the permanent magnet 40 abuts magnetic frame 42 intermediate the polar extremities 43 and 44. Here, it will be readily seen that when coil section 30 is energized by connecting a suitable source of direct current across leads '27;and 29so that the polar extremity 43 is polarized north, vane 17 being at north polarity by virtue of its magnetic pivotal connection to the north polar extremity of permanent magnet 40 will be violently and rapidly repelledtowardpolar extremity 44, thereby opening branch waveguide section 2 and closing and short-circuiting branch waveguide section 3. Likewise, energization of electromagnet winding section 31 so that polar extremity 44 is at north polarity causes vane 17 to be violently and suddenly repelled toward the other polar extremts/1 In the'operation ofbothembodiments of this invention, neitherof theelectromagnet coil sections 30 and 31 will normally be energized so that the vane 17 will, due to residual magnetism, be normally engaged with the polar extremity to which it was switched by the last energization of the electromagnet. The appropriate electromagnet coil section is thus preferably pulsed with an appropriate voltage thereby'suddenly to shift the magnetic vane 17 to the opposite position. It will .be seen that because of the extremely fast action of the magnetic vane 17 in being magnetically repelled from one polar extremity to the other, the energizing pulse impressed on the appropriate coil section of the electromagnet may be of extremely short duration.

It will now be readily apparent that the magnetic vane 17, by virtue of its magnetic pivotal hinging, has essentially no friction, which fact, combined with the strong magnetic fields involved, provides exceedingly fast switching action. It will further be seen that the edges of the vane are magnetically sealed to the adjacent waveguide wall thus effectively short circuiting and closing that branch waveguide section. Further, due to the magnetic attraction between the vane and the adjacent magnetic polar extremity, there is little tendency for the vane to bounce during the switchingoperation. It has further beenfound thatsince the vane is in the H plane of the waveguide assembly, the standing waveguide ratio is good and ,a goo d impedance match to the main waveguide section4is provided during the switching operation.

It wil further be seen that the switching action in my improved device is provided by repulsion of magnetic poles rather than repulsion of magnetic material, thereby providing extremely fast switching action.

While I have described above the principles of my invention'in connection with specific apparatus, it is to be clearlyunderstood that this description is made only by way of-ex'ample and not'as a limitation-to the scope of my t m. .-v

What is claimed is. a

1. A waveguide assembly comprising: two branch waveguide sections merging into a main waveguide section, said main waveguide section having an opening formed therein; and switching means for selectively connecting one of said branch waveguide sections to said main waveguide section, and comprising a vane formed of magnetic material with a portion extending through said opening into said main waveguide section and having a first position short-circuiting one of said branch waveguide sections and a second position short-circuiting the other of said branch waveguide sections, first magnetic means on the exterior of said waveguide sections, said vane being mounted magnetically adjacent one polar extremity of said first magnetic means for movement between said first and second position whereby said vane has the same magnetic polarity as said one polar extremity, and second magnetic means on the exterior of said waveguide sections with said vane magnetically between oppositely polarized extremities thereof, one of said magnetic means being permanently polarized in one direction and the other being selectively polarized in opposite directions whereby said vane is magnetically switched from one position to the other.

2. A waveguide assembly comprising: two branch Waveguide sections merging into a main waveguide section, said main waveguide section having an opening formed therein; and switching means for selectively connecting one of said branch waveguide sections to said main waveguide section, and comprising a vane formed of magnetic material with a portion extending through said opening into said main waveguide section and having a first position short-circuiting one of said branch waveguide sections and a second position short-circuiting the other of said branch waveguide sections; first magnetic means on the exterior of said waveguide sections; said vane being mounted on one polar extremity of said first magnetic means for movement between said first and second positions whereby said vane has the same magnetic polarity as said one polar extremity, and second magnetic means on the exterior of said waveguide sections with said vane magnetically between oppositely polarized extremities thereof, one of said magnetic means being permanent- 1y polarized in one direction and the other being selectively polarized in opposite directions whereby said vane is magnetically switched from one position to the other.

3. A waveguide assembly comprising: two branch waveguide sections merging into a main waveguide section, said main waveguide section having an opening formed therein; and switching means for selectively connecting one of said branch waveguide sections to said main waveguide section, and comprising a vane formed of magnetic material with a portion extending through said opening into said main waveguide section and having a first position short-circuiting one of said branch waveguide sections and a second position short-circuiting the other of said branch waveguide sections; first magnetic means on the exterior of said waveguide sections, said vane being pivotally mounted on one polar extremity of said first magnetic means for movement between said first and second position whereby said vane has the same magnetic polarity as said one polar extremity, and second magnetic means on the exterior of said waveguide sections with said vane magnetically between oppositely polarized extremities thereof, one of said magnetic means being permanently polarized in one direction and the other being selectively polarized in opposite directions whereby said vane is magnetically switched from one position to the other.

4. A waveguide assembly comprising: two branch waveguide sections merging into a main waveguide section, said main waveguide section having an opening formed therein, and switching means for selectively connecting one of said branch waveguide sections to said main waveguide section, and comprising a vane formed of magnetic material with a portion extending through said opening into said main waveguide section and having a first position short-circuiting one of said branch waveguide sections and a section position short-circuiting the other of sad branch waveguide sections; a first longitudinally polarized magnetic member on the exterior of said waveguide sections with said vane being pivotally mounted on one polar extremity thereof for movement between said first and second positions whereby said vane has the same magnetic polarity as said one polar extremity, and a second longitudinally polarized magnetic member on the exterior of said waveguide section with its polar extremities magnetically embracing said vane, one of said magnetic members being a permanent magnet and the other being an electromagnet selectively energizable for polarization in opposite directions whereby said vane is magnetically switched from one position to the other.

5. A waveguide assembly comprising: two branch waveguide sections merging into a main waveguide section, said main waveguide section having an opening formed therein; and switching means for selectively connecting one of said branch waveguide sections to said main waveguide section, and comprising a vane formed of magnetic material with a portion extending through said opening into said main waveguide section and having a first position short-circuiting one of said branch waveguide sections and a second position short-circuiting the other of said branch waveguide sections; a first e1ongated longitudinally polarized magnetic member on the exterior of said waveguide section, one end of said first magnetic member having a groove formed therein, said vane having another portion pivotally seated in said groove thereby forming a magnetic pivot for said vane whereby said vane has the same magnetic polarity as said one end of said first magnetic member and may be pivotally moved from said first position to said second position, and a second longitudinally polarized magnetic member on the exterior of said waveguide section with its polar extremities magnetically embracing said vane, one of said magnetic members being a permanent magnet and the other being an electromagnet selectively energizable for polarization in opposite directions whereby said vane is magnetically switched from one position to the other.

6. A waveguide assembly comprising: two branch waveguide sections merging into a main waveguide section, said main waveguide section having an opening formed therein; and switching means for selectively connecting one of said branch waveguide sections to said main waveguide section, and comprising a vane formed of magnetic material with a portion extending through said opening into said main waveguide section and having a first position short-circuiting one of said branch waveguide sections and a second position short-circuiting the other of said branch waveguide sections; a first longitudinally polarized magnetic member on the exterior of said waveguide sections with said vane being pivotally mounted on one polar extremity thereof for movement between said first and second positions whereby said vane has the same magnetic polarity as said one polar extremity, a second longitudinally polarized magnetic member on the exterior of said waveguide section with its polar extremities magnetically embracing said vane, one of said magnetic members being a permanent magnet and the other being an electromagnet selectively energizable for polarization in opposite directions whereby said vane is magnetically switched from one position to the other, and means cooperating with said second magnetic member and said vane forming a return magnetic path for said: first magnetic member.

7. A waveguide assembly comprising: two branch wave-- guide sections merging into a main waveguide sectionz thereby defining a generally Y-shaped configuration, the end of said main waveguide section intermediate said branch waveguide sections having an opening formed therein; and switching means for selectively connecting:

one'end of said fir'stmagnetic' member, and a second longitudinally polarized magnetic member having its polar extremities magnetically embracing said main'waveguidesection adjacent the'merge'r of said branch waveguide sections therewith whereby said vane is magneti-' cally" disposed between said polar extremities of said secondmagnetic member, one ofsaidm'agnetic members being a permanent magnet'and'the other being an'electromagnet selectively energizable for polarization in opposite directions whereby saidvane is magnetically switched from one position to-the' other.

8; A waveguide assembly comprising: two branch waveguide sections merging into a main'waveguide section thereby defining a generally Y-shaped configuration, the end of said main waveguide section intermediate said branch waveguide sections having an opening formed therein; and switching means for selectively connecting one of said branch waveguidesections to said main waveguide section and comprising a vane formed of relatively thin'magnetic material with a position closing and shortcircuiting one of said branch waveguide sections and a second position closing and short-circuiting the other of said branch waveguide sections; a first elongated longitudinaily polarized magnetic member positioned between said branch waveguide sections and having one end adjacent said opening, said vane being magnetically pivoted to said one end of said first magnetic member for movement between said first and second positions whereby said vane has the same magnetic polarity as said one end of said first magnetic member, and a second longitudinally polarized magnetic member having its polar extremities magnetically embracing said main waveguide section adjacent the merger of said branch waveguide sections therewith whereby said vane is magnetically disposed between said polar extremities of said second magnetic membe one of said magnetic members being a permanent magnet and the other being an electromagnet selectively energizable for polarization in opposite directions whereby said vane is magnetically switched from one position to the other, the other end or" said first magnetic member being magnetically connected to said second magnetic member intermediate said polar extremities thereof thereby for'ming with said vane a magnetic return path for said first magnetic member.

9. A waveguide assembly comprising: two branch waveguide sections merging into a main waveguide sec tion, said main waveguide section having an opening formed therein; and switching means for selectively connecting one of said branch waveguide sections to said main waveguide section, and comprising a vane formed of magnetic material with a portion extending through said opening into said main waveguide section and having a first position short-circuiting' one of said branch waveguide sections and a second position short-circuiting the other of said branch waveguide sections; an elongated longitudinally polarized permanent magnet on the exterior of said waveguide section, said vane being magnetically pivoted at one end of said permanent magnet for move ment between said first and second positions whereby said vane has the same magnetic polarity as said one end of said permanent magnet, and an electromagnethaving an elongated magnetic core itt its ends embracing said main waveguide section adjacent the merger of said branch waveguide sections therewith, said electromagnet having a-coilselectively energizable for polarization'of said core in opposite directions whereby said vane magnetically switchedfrom one position-to the other.

10. waveguide assembly comprising: two branch waveguide sectionsmerging'into a main waveguide section, said main waveguide section having an opening formed thereingand switching means for selectively connecting one of said branch waveguide sections to said mainwaveguide section, and comprising a vane formed of magnetic material with a portion extending through said pivoted at one end of said permanent magnet for movement between said first and second positionswhereby said vane has the same magnetic polarity as said one end of said permanent magnet, and an electromagnet having an elongated magnetic core with its ends embracing said main waveguide section adjacent the merger of said branch waveguide sections therewith, said electromagnet having a coil selectively energizable for polarization of said core in opposite directions whereby said vane is magnetically switched from one position to the other, the other end of said permanent magnet being magneti-' cally connected to said electromagnet core intermediate its'ends thereby forming with said vane a magnetic return path for said permanent magnet.

ll. A waveguide assembly comprising: two branch waveguide sections merging into a main waveguide section, said main waveguide section having an opening formed therein; and switching means for selectively connecting one of said branch Waveguide sections to said main waveguide section, and comprising a vane formed of' magnetic material with a portion extending through said opening into said main waveguide section and having a first position short-circuiting one of said branch waveguide sections and a second position short-circuiting the other of said branch waveguide sections; an electromagnet on the exterior of said waveguide section having an elongated magnetic core, said vane being magnetically pivoted at one end of said core for movement between said first position and said second position whereby said vane has the same magnetic polarity as said one end of said electromagnet core, and a longitudinally polarized permanent magnet having its polar extremities embracing said main waveguide section adjacent the merger of said branch waveguide sections therewith, said electromagnet having a coil selectively energizable for polarization of said core in opposite directions whereby said vane is magnetically switched from one position to the other.

12. A waveguide assembly comprising: two branch waveguide sections merging into a main waveguide section, said main waveguide section having an openingformed therein; and switching means for selectively connecting one of said branch waveguide sections to said main waveguide section, and comprising a vane formed of magnetic material with a portion extending through said opening into said main wave guide section and having a first position short-circuiting one of said branch waveguide sections and a second position short-circuiting the other of said branch waveguide sections; an electromagnet on the exterior of said waveguide section having an elongated magnetic core, said vane being magnetically pivoted at one end of said core for movement between said first position and said second position whereby said vane has the same magnetic polarity as said one end of said electromagnet core, and a longitudinally polarized permanent magnet having its polar extremities embracing said main waveguide section adjacent the merger of said branch we i'de sections therewith, said eiectromagnet having a coil selectively energizable for polarization of said core in opposite directions whereby said vane is magnetically switched from one position to the other, said electromagnet core having its other end magnetically connected to said permanent magnet intermediate said polar extremities thereby forming with said vane a magnetic return path for said electromagnet.

13. A waveguide assembly comprising: two branch waveguide sections merging into a main waveguide section thereby defining a generally Y-shaped configuration, the end of said main waveguide section intermediate said branch waveguide sections having an opening formed therein; switching means for selectively connecting one of said branch waveguide sectio'ns to said main waveguide section and comprising a vane formed of relatively thin magnetic material with a first position closing and shortcircuiting one of said branch waveguide sections and a second position closing and short-circuiting the other of said branch waveguide sectio'ns, a first elongated longitudinally polarized magnetic member positioned between said branch waveguide sections and having one end adjacent said opening, said vane being magnetically pivoted to said one end of said first magnetic member for movement between said first and second positions whereby said vane has the same magnetic polarity as said one end of said first magnetic member, and a second longitudinally polarized magnetic member having its polar extremities magnetically embracing said main waveguide section adjacent the merger of said branch waveguide sections therewith whereby said vane is magnetically disposed between said polar extremities of said second magnetic member, one of said magnetic members being a permanent magnet and the other being an electromagnet selectively energizable for polarization in opposite directions whereby said vane is magnetically switched from one position to the other; and a frame structure formed of magnetic material supporting said waveguide sections, said second magnetic member, and the other end of said first magnetic member, and forming with said vane a return magnetic path for said first magnetic member.

14. A waveguide assembly comprising: two branch waveguide sections merging into a main waveguide section thereby defining a generally Y-shaped configuration,

said main waveguide section having an end portion intermediate said branch wave guide sections and having an elongated opening formed therein; a cover member for said opening formed of magnetic material and having a po'rtion with a longitudinal groove formed therein extending into said opening; an elongated vane formed of magnetic material positioned in said main waveguide section and having one edge pivotally mounted in said groove for movement between a first position closing and short-circuiting one of said branch waveguide sections and a second position closing and short-circuiting the other of said branch waveguide sections; a generally U-shaped frame member formed of magnetic material having one leg portion supporting said main waveguide section and its other leg portio'n supporting said branch waveguide sections; an electromagnet positioned between said branch waveguide sections and having an elongated core member with one end thereof secured to said other leg portion of said frame member and its other end abutting said cover member; a pair of elongated oppositely polarized permanent magnets respectively having one end mounted on said one leg portion of said frame member on opposite sides of said main Waveguide section; a pole piece member respectively mounted on the other ends of said permanent magnets and abutting said -main waveguide section adjacent the merger of said branch waveguide sections therewith; said electromagnet having a coil selectively energizable for polarization of said core in opposite directions whereby said vane is magnetically pivoted to said one end of said core and has the same magnetic polarity as said one end of said core, energization of said electromagnet coil in opposite senses causing said vane to be magnetically switched from one position to the other thereby connecting one or the other of said branch waveguide sections to said main waveguide section.

References Cited in the file of this patent UNITED STATES PATENTS 1,333,247 Cummings Mar. 9, 1920 2,752,450 Fonlkes et a1. June 26, 1956 2,827,613 Robinson et a1. Mar. 18, 1958 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patm: N0. 2 ,917, 71?? i William To Brown.

3011mm 6, line ,4, for ",sacrbion position" read st-lcond position line 5, for "sad" read. W said Signed and sealed this 31st day of May 1960.

(SEAL) fittest:

KARL H, AXZJNE ROBERT C. WATSON Attesting Officer Commissioner of Patents UNITED STATES PATENT OFFICE Patent No, 2,917,719 December 15, 1959 1 of the above numbered patent requiring correction and that the said Letters Patent should readas corrected below.

Column 6, line for *eeotion position" seeond position line 5, for "god" W said e Signed and sealed this 31st day of May 1960.,

{SEALII fittest:

KARL A LINE ROBERT C. WATSON Attesting @fiicer Commissioner of Patents 

